[Bindings] Cache handles for dictionary keys on V8PerIsolateData.

third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.h

Index: third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.h b/third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.h
index 17d08c74f148512e7c4658abccb6ca99c46c430f..5f46678c04b7a288afe5f7fca047e47f82678ff4 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.h
+++ b/third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.h
@@ -152,6 +152,13 @@ class CORE_EXPORT V8PerIsolateData {
       v8::Local<v8::Signature>,
       int length);
 
+  // Obtains a pointer to the set of well-known dictionary keys identified by
+  // the lookup key, or creates it from an array of static strings.
+  // TODO(jbroman): v8::Eternal::Get should be const.
+  const v8::Eternal<v8::Name>* findOrCreateKeys(const void* lookupKey,
+                                                const char* const keys[],
+                                                size_t keyCount);
+
   bool hasInstance(const WrapperTypeInfo* untrusted, v8::Local<v8::Value>);
   v8::Local<v8::Object> findInstanceInPrototypeChain(const WrapperTypeInfo*,
                                                      v8::Local<v8::Value>);
@@ -238,6 +245,9 @@ class CORE_EXPORT V8PerIsolateData {
   V8FunctionTemplateMap m_operationTemplateMapForMainWorld;
   V8FunctionTemplateMap m_operationTemplateMapForNonMainWorld;
 
+  // Contains direct pointers to well-known dictionary keys.
+  HashMap<const void*, Vector<v8::Eternal<v8::Name>>> m_keyMap;
+
   std::unique_ptr<StringCache> m_stringCache;
   std::unique_ptr<V8HiddenValue> m_hiddenValue;
   std::unique_ptr<V8PrivateProperty> m_privateProperty;